Flame retardant systems

ABSTRACT

The known compound, 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4methanonaphthalene-5,8-diol (I) is an excellent flame retardant for ABS resins and polyurethanes, particularly, polyether-based polyurethanes. Compound I also forms novel molecular complexes with weak bases such as pyridine, pyridine HCl, pyridine oxide, dimethylsulfoxide and dimethylformamide, and which are excellent flame retardants for ABS resins. Compound I also exhibits unusual synergistic flame retardant effects in ABS resins and other polymers when used together with certain additives that are not themselves flame retardants.

limited States Patent [191 Little et a1.

[451 Aug. 27, 1974 FLAME RETARDANT SYSTEMS Inventors: Julian R. Little, Hendersonville,

NC; Walter Nudenberg, West Caldwell, N.J.; Yong S. Rim, Waterbury, Conn.

Uniroyal, Inc., New York, N.Y.'

Apr. 3, 1973 Related US. Application Data Continuation-in-part of Ser. No. 80,747, 0m. 14,

US. Cl. 260/876 R, 252/81, 260/2.5 AJ, 260/37 N, 260/41.5 R, 260/45.7 R, 260/45.7 S, 260/45.8 N, 260/45.8 NZ, 260/45.9 R, 260/561 R, 260/244 R, 260/290 S, 260/561 R3n, 260/607 A, 260/619 F Int. Cl. C08f 45/58, C08g 51/58 Field of Search 260/45.8 N, 45.95 L, 37 N, 260/41.5, 45.7 R, 2.5 A], 876 R, 619 F,

326.5 S, DIG. 24; 252/81; 106/15 FP References Cited UNITED STATES PATENTS [73] Assignee:

[22] Filed:

[21] Appl.No.:

1970, abandoned.

Eichhorn 252/81 3,202,567 8/1965 Muri et a1. 106/15 3,326,832 6/1967 Rauschenbach et a1. 260/45.75 3,396,201 8/1968 Weil et a1. 260/45.7 3,418,263 12/1968 Hindersinn et al. 260/23 3,442,980 5/1969 Grabowski 260/880 3,474,464 10/ 1969 Matthews et al. 260/45.75 3,678,116 7/1972 Carlson 260/619 Primary ExaminerV. P. Hoke Attorney, Agent, or FirmHubbell, Cohen & Stiefel [57] ABSTRACT and which are excellent flame retardants for ABS resins. Compound I also exhibits unusual synergistic flame retardant effects in ABS resins and other polymers when used together with certain additives that are not themselves flame retardants.

18 Claims, N0 Drawings 1 FLAME RETARDANT SYSTEMS CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of copending application Ser. No. 80,747, filed Oct. 14, 1970, now abandoned the contents of which are expressly incorporated herein by reference.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates to the field of flame retardants ancy and this inadequacy represents one of the major obstacles to the use of these materials.

Presently, the most widely used fire retardant chemicals are antimony trioxide and organohalogen compounds, the best known being chlorendic anhydride l- ,4,5 ,6,7,7-hexachlorobicyclo[2.2.1]-hept-5-ene2,3- dicarboxylic anhydride); tetrabromoor tetrachlorophthalic acid; l,4'-isopropylidenebis (2,6- dichlorophenol) [tetrachlorobisphenol A] or the corresponding bromine-containing compound; chloran, i.e., 2,3-dicarboxyl-5,8endomethylene-5,6,7, 8,9,9- hexachloro- 1 ,2,3,4,4a,5 ,8,8a-octahydronaphthalene anhydride; chlorinated paraffins; and dechlorane (dihexachlorocyclopentadiene).

The foregoing halogen compounds have only limited utility in polymer compositions due to a number of disadvantages. For example, when such halogen compounds are incorporated into a polymer, various physical properties of the polymer are modified, e.g., change in melt viscosity which requires higher processing temperatures, decrease in light stability, decrease in thermal stability, increase in density, adverse effects on heat distortion point, etc.

Some of these disadvantages have been overcome by the use of halogen-containing polymers as the flame retardant additive. Typical of such polymers are 2- chlorobutadiene, polyvinylchloride, chlorinated polyethylene and chlorosulfonated polyethylene. There are also, however, serious disadvantages associated with the use of such polymers. Among these are: (1) large amounts of halogen-containing polymers are required in order to obtain satisfactory fire retardancy due to the relatively low halogen content thereof; (2) the halogencontaining polymers have low thermal stabilities; and (3) the blending of the halogen-containing polymer with the polymer to be rendered flame retardant usu ally requires expensive processing techniques.

In addition, it is known from US. Pat. No. 3,678,1 16 that 1 ,2,3,4,9,9-hexachloro-l ,4-dihydrol ,4- methanonaphthalene-S,8-diol (I) is useful as a flame retardant for polymer systems such as polyesters.

SUMMARY OF THE INVENTION We have discovered a new system of chemical fire retardants for polymers such as acrylonitnlebutadiene-styrene (ABS) polymers and polyurethane polymers, hereinafter referred to as polyurethanes, and in particular, to polyether-based polyurethanes. The new system is based on the discovery that the known compound 1 ,2,3,4,9,9-hexachloro-l ,4-dihydro-l ,4- methanonaphthalene-S,8-diol (I) possesses unexpected and superior flame retardant properties with respect to ABS and polyurethanes. Thus, notwithstanding that compound I is known, from US. Pat. No. 3,678,l 16, to be effective in rendering polyesters flame retardant, we have now discovered that this compound is dramatically better in rendering ABS and polyurethanes flame resistant than it is in rendering polyesters flame retardant.

Accordingly, in one aspect thereof, the present invention provides a flame retardant composition comprising an ABS polymer or a polyurethane and an amount of compound I which is effective to tender the polymer flame retardant. This effective amount varies somewhat depending on which polymer is being rendered flame retardant. Thus, when as little as about 6.0 parts of compound I are incorporated into parts by weight of ABS, there is imparted to the ABS, consider able flame retardancy. With polyurethanes, on the other hand, as little as about 3.0 parts per hundred of compound I imparts good flame retardancy to the polyurethane, and with about 5.0 parts per hundred of compound I, the flame retardancy of the polyurethane is outstanding. The invention also provides a method of rendering ABS and polyurethanes flame retardant by incorporating in the polymer an effective amount of compound I.

We have also discovered that there is an unusual and unexpected synergistic effect exerted upon compound I by certain additives which are not themselves particularly effective as flame retardants and which do not synergize the effect 'of other known flame retardants including known polyhalogenated organic materials. In particular, these additives synergize the ability of compound I to impart flame retardancy to ABS polymers. Among these additives there are urea, magnesium oxide, magnesium sulfide, magnesium acetylacetonate, polyvinylchloride and other materials which generate stable free radicals, such as trityl chloride, (C H CCl and 1 tioned additives to compound I is given in the following Table I:

TABLE I Weight ratio,

additlvezeom- Additive pound (l) Urea 3%}:10 Magnesium oxide. 1. 4-4. 4:7. 7-10 Magnesium sulfide.. 2. 8:7. Magnesium acetylacetonate. 2. 8:7. 0 Polyvinylehloride 15 z 6 Trityl chloride 4 2:11. 1

The present invention also provides novel flame retardant compositions comprising an ABS polymer and an effective amount of the above-described synergistic composition, as well as a method for rendering an ABS polymer flame retardant by incorporating into the ABS an effective amount of said synergistic composition.

We have also discovered, and the invention provides, a novel class of molecular complexes of compound I and weak bases such as pyridine, pyridine oxide, pyridinium hydrochloride, pyridinium methobromide, pyridinium methoiodide, dimethylsulfoxide and dimethylformamide.

These novel molecular complexes have the formula:

wherein A is pyridine, pyridine oxide, pyridinium hydrochloride, pyridinium methobromide, pyridinium methoiodide, dimethyl sulfoxide or dimethylformamide, and n is l or 2.

The invention further provides flame retardant compositions comprising an ABS polymer and an effective amount of the above defined molecular complex. This effective amount will vary depending on which molecular complex is incorporated in the ABS polymer. Generally, it is at least about 4.0 parts per 100 parts by weight of the ABS polymer and preferably, between about and parts per 100 parts of the ABS polymer.

Finally, the invention provides a method of rendering an ABS polymer flame retardant by incorporating in the polymer an effective amount of the molecular complex.

The polymeric mateials, i.e., ABS polymers and polyurethanes, are rendered flame retardant by incorporation of the flame retardant systems of the present invention into the polymer.

The flame retardant system may readily be incorporated into the polymeric material by a variety of methods depending on the nature of the polymer. Thus, for example, for those polymers which are adaptable to milling procedures and the like, the flame retardant system may simply be physically blended with the preformed polymer. With other types of polymers which require compounding, e.g., an uncured elastomer, or

cannot readily be physically blended with other materials after formation of the polymer, the flame retardant system may be added to the compounding mixture of polymerization mixture.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the following description and examples, reference will be made to ABS polymers and polyurethanes.

ABS (acrylonitrile-butadiene;styrene) polymers are members of the group known as gum plastics. These materials, also referred to resin-rubber blends generally comprise a mixture of a hard, relatively brittle polymer (resin) and a minor portion of a relatively soft, rubbery polymer.

Suitable gum plastics which can be used in the present invention are described in US. Pat. No. 3,489,821, particularly column 1, line 52 column 4, line 34 thereof, US. Pat. No. 3,489,822, particularly column 1, line 51 column 4, line 45 thereof, said patents being incorporated by reference herein.

The ABS resins which best characterize the gum plastics, are made in a well known manner by interpolymerizing styrene and acrylonitrile monomers in the presence of a rubber which is either polybutadiene or a copolymer of butadiene and styrene, said copolymer containing not more than 10% by weight of combined styrene based on the sum of the weights of butadiene and styrene. Polymerization systems such as emulsion, mass, or solution are also applicable for ABS preparation. The manufacture of such ABS resins is shown in detail in US. Pat. Nos. 2,820,773, 2,802,809, 3,238,275 and 3,260,772, particularly column 3, lines 32-50 thereof, each of said patents being incorporated by reference herein. The ABS graft polymer-containing resins used in the present invention can be made with varying rubber content, this conveniently being achieved in accordance with known practice (e.g., as shown in US. Pat. No. 2,820,773) by admixing additional acrylonitrile-styrene copolymer latex of grafted material, and co-precipitating.

it is further possible to substitute for the acrylonitrilestyrene resinous portion, mixtures of styreneacrylonitrile resin and a vinyl resin such as vinyl chloride polymer (particularly polyvinylchloride).

in place of using acrylonitrile itself for the preparation of the polymer, one may substitute for part or all of the acrylonitrile, equivalent similar monomers such as homologs or substitution products of acrylonitrile, e.g., methacrylonitrile and ethacrylonitrile.

Similarly, in place of using styrene itself in the preparation of the polymers used in the invention, one may substitute, for part or all of the styrene, equivalent monomers including substitution products of styrene, such as'alkyl-substituted styrenes, including alpha-alkyl styrenes and nuclear alkyl-substituted styrenes such as alpha-methyl-styrene, other nuclear methyl-substituted styrenes, nuclear monoethyl-substituted styrenes, the monoand di-chloro styrenes, etc.

Suitable polyurethanes are foamed and unfoamed rigid polyurethanes, i.e., organic diisocyanate-modified polyethers, polyesters. polyesterpolyethers and polyester-polyamides, both saturated and olefinically unsaturated; and in particular, organic diisocyanate-moditied polyethers. Such polymers are generally obtained from the reaction of a polyisocyanate, usually a diisocyanate. with a polyfunctional compound containing activehydrogen groups, such as polyalkylene ether glycols, hydroxy-terminated polyesters, castor oil and polyester amides as well as mixtures of two or more of these classes of polyfunctional compounds. The material used for reaction with the polyisocyanate to make the polyure thane is frequently a polyethcr or polyester glycol having a molecular weight of from 400 to 6000, preferably in the 1000-2000 range. Mention may be made of polyethers, such as polypropylene glycol, polypropyleneethylene glycol and polytetramethylene glycol. Men tion may also be made of chain extended polyesters made from a glycol (e.g., ethylene and/or propylene glycol) and a saturated dicarboxylic acid (e.g., adipic acid). Usually the starting glycol contains from 2 to carbon atoms and the acid contains from 4 to 12 carbon atoms. Polyethylene adipate, polyethylene adipatephthalate, polyneopentyl sebacate, etc. maybe mentioned. Small amounts of tri-alcohols such as trimethylolpropane or trimethylolethane may be included.

mer were prepared by mixing compound 1 and the ABS polymer in a conventional two roll mixing mill at 320F. for 5 minutes. The compounded material was then molded to /8 inch thickness in a press. The molded sheets, after being cooled, were cut into strips and the strips were tested for fire retardanee using the specified tests.

The results of the fire retardance tests are set forth in Table 11. (In the Tables, SE means self-extinguishing and NB means non-buming.)

a known commercial fire retardant Among the suitable polyisocyantes may be mentioned mand p-phenylene diisocyantes; toluene diisocyanate; p,p'-diphenylmethane diisocyanate; 3,3'-dimethyl (or dimethoxy )-4,4-biphenyl diisocyanate; 1 ,5- naphthylene diisocyanate; p,p',p"-triphenylmethane triisocyanate; p-phenylene diisothiocyanate, etc. The isocyanate is, of course, used in an amount at least equivalent to the hydroxyl groups in the starting polymer; larger quantities of diisocyanate favor formation of liquid prepolymer. Generally, the molar ratio of diisocyanate to glycol is in the 1.211 to 3:1 range. For additional examples of suitable starting materials for making polyurethanes, reference may be had to the following: Otto Bayer in Angewandte Chemie, A/59 (1947), No.9, p. 264; and US. Pat. No. 3,105,062 in corporated herein by reference. Suitable polyurethanes are described in US. Pat. No. 3,412,071, particularly column 5, line 44 column 4, line 6 thereof, US. Pat. Nos. 2,734,045 and 3,457,326, each of said patents being incorporated by reference herein.

The following examples illustrate the fire retardant effect of various amounts of compound I on an ABS polymer. The blends of compound 1 and the ABS poly- From the data, it can be seen that compound 1 is a much more effective flame retardant in ABS polymers than is chloran, a known flame retardant. Thus, when about 15 pph of compound I were added to ABS, the oxygen index increased from 18.3% (control) to 28.0%, an increase of 9.7%. When 15 pph of chloran were added to ABS, the oxygen index only increased from 18.3% (control) to 20.3%, an increase of 2.0%. Compound 1 is therefore 4.85 times more effective than chloran in making ABS flame retardant:

TABLE 111 BURN POLY- RATE URE- COMPOUND CHLORAN lnehes/ OXY- THANE (1) GEN EXAMPLE (parts) (parts) (parts) DRIPPING Minutes Index 7:

10 0 XXX 1.03 22.3 11 do. 3 XX 0.53 23.1

TABLE III Cont nued BURN POLY- RATE URE- COMPOUND CHLORAN Inches/ OXY- THANE (I) GEN EXAMPLE (parts) (parts) (pans) DRIPPING Minutes lndex l2 do. 5 X S15 24. l 13 do. l None SF. 25.4 14 do. 15 None NB 3].} 15 do. 25 None NB 33.) I6 do; XX 0.60 23.l l7 do. IO XX 0.68 22.) I8 do. XX SF. 22.8 19 do. 25 X SE 22.5

XXX heavy dripping XX moderate dripping X light dripping One of the most serious problems encountered in the use of FR polyurethane elastoplastics for wire coatings is a dripping phenomena during combustion. Most inorganic flame retardants cannot be used for the polyurethane because of severe degradation of the physical properties thereof. As can be seen from the data in Table III, the use of compound I substantially diminishes the dripping and with 15 pph of compound I, the polyurethane is rendered non-burning and nondripping.

Compound I is a much more effective flame retardant than chloran as can be seen from the oxygen index test data in Table III. Thus, when 15 pph of compound I are added to the polyurethane, the oxygen index increased from 22.3% to 3l.3%, an increase of 9.0%. When 15 pph of chloran were added to the polyurethane, the oxygen index only increased from 22.3% to 22.8%, an increase of 0.5%. Compound I is therefore 18 times more effective than chloran in making polyurethane flame retardant:

By way of comparison, the following Examples 20-25 illustrate the effects of compound I and chloran on two different polyesters.

As can be seen from the data in Table IV, compound I and chloran both have about the same effect in making two different polyesters flame retardant. However, as seen from the data in Tables II and III, compound I is much more effective than chloran in both ABS and polyurethanes. Thus, the discovery that compound I is so clearly superior in rendering ABS and polyurethanes flame retardant is quite an unexpected discovery.

The following examples illustrate the synergistic flame retardant effect between compound I and the additives described above when they are incorporated in an ABS polymer.

In Examples 26-31, varying amounts of compound I and the stable, free radical generating additives trityl chloride and 0 l N S indices were determined.

TABLE IV COMPOUND CHLORAN OXY- (I) GEN EXAMPLE POLYESTER (Parts) (parts) (parts) Index KODEL* POLYTEX 20 I00 0 0 23.95 2! I00 l5 0 25.09 22 I00 0 15 26.47 23 I00 0 0 23.95 24 I5 0 26.47 25 I00 0 l5 25.93

*Kodel Eastman Kodak polyester *fgolylex lldustizilinishcs Corp. polyester TABLE V Oxygen ABS Compound index, Example (parts) (1) (parts) Additive Parts percent E .T I00 Ill 3 30. J .h 100 I'd- S 5 30. .2 :9 ton in m 2H. 4

30 100 11. I 'lrltyl chloride. l. 3 3' f 31 100 (I0 ll) 3.

As can be seen from the data in Table V, both additives synergize the flame retardant effect of compound I. The use of 3 parts per hundred of increases the oxygen index from 27.7% (compound I control) to 30.9%, an increase of 3.2%, while the use of 4.1 parts per hundred of trityl chloride increases the oxygen index even more, i.e., from 27.7% to 32.4%, an increase 4.7%.

1 5 From the data in Table VII, it can be seen that the addition of 3 parts per hundred of urea together with TABLE VII ABS ADDITIVES (parts) BURN RATE OXY- GEN EXAMPLE (parts) COMPOUND CHLORAN UREA Inches/Minutes Index 43 do. 10 3 SE 33.3

44 do. 10 6 SE 30.3

The known flame retardants, chloran and chlorendic anhydride do not exhibit this synergism with the above additives.

In Examples 32-40, varying amounts of compound I and magnesium oxide, magnesium sulfide and magnesium acetylacetonate were incorporated in an ABS polymer and the flame retardant effects thereof were determined by both burn rate and oxygen index. The data are given below in Table VI.

alone is not a flame retardant and the addition of urea parts of compound I considerably improves the flame retardancy of an ABS polymer in comparison with the use of 10 parts of compound I alone. Thus, with 3 parts of urea, the polymer becomes self-extinguishing and the oxygen index increases from 27.0% to 33.3%.

This synergism is quite unexpected because urea to chloran or chlorendic anhydride does not improve the flame retardancy thereof.

TABLE VI BURN MAGNE- SIUM MAGNE- MAGN E- ACETYL- RATE SIUM SIUM ABS COMPOUND OXIDE SULFIDE ACETON- Inches/ OXY (l) ATE GEN EXAMPLE (pans) (parts) (parts) (parts) (parts) Minutes Index 32 100 7.7 O O 0 1.48 24.06 33 do. do. 1.4 0 0 0.98 24.13 34 do. do. 2.8 O 0 SE 26.76 35 do. do. 4.2 0 0 SE 27.25 36 do. 10 0 0 0 1.51 26.96 37 do. do. 3.0 O 0 SE 27.30 38 do. do. 4.4 0 NB 27.63 39 do. 7.0 0 2.8 0 SE 25.27 40 do. do. 0 0 2.8 SE 25.68

As can be seen from the data in Table VI, magnesium oxide exerts a strong synergistic effect on compound I in ABS polymer. This effect is more clearly shown by the burn rate test than by the oxygen index although the latter also shows a considerable enhancement over the results obtained when compound I is used alone.

Thus, 7.7 parts of compound I per 100 of ABS showed an oxygen index of about 24.1 and burned relatively fast. However, the addition of 2.8 parts or more of magnesium oxide made the composition selfextinguishing and raised the oxygen index to about 27. When 3 or more parts of magnesium oxide were mixed with 10 parts of compound I in ABS the composition In Examples 46-50, varying amounts of compound I, polyvinylchloride (PVC) and the known flame retardant, Dechloran 602 were incorporated into an ABS polymer and the flame retardant effects thereof were determined using both the burn rate and oxygen index tests. The data are set forth in Table VIII:

The data in Table VIII show that the addition of 15 parts per hundred of PVC increases the oxygen index by 4.3% and makes the polymer composition selfextinguishing. In contrast, PVC alone or in combination with Dechloran 602 has no appreciable effect on either of the two criteria used to evaluate flame retardancv.

I l l 2 TABLE VIII BURN ADDlTlVES (parts) RATE ABS DECHLO- lnches/ OXY RAN GEN EXAMPLE (parts) COMPOUND PVC 602 Minutes Index 46 100 6 0 1.60 23.2 47 do. 6 0 SE 27.5 48 do. 0 15 0 1.70 19.3 49 do. 0 0 15 1.60 20.4 50 C10. 0 15 7.7 1.50 20.6

In the following Examples, the preparation of the EXAMPLE52 novel molecular complexes of the invention will be de- 5 scribed. In these Examples, all parts are by weight un- Prepamnon of molecular Complex 9 y l 1 otherwise i di d and l,2,3,4,9,9-hexachloro-1,4-d1hydro-1,4-

EXAMPLE 51 Preparation of l ,2,3 ,4,9,9-hexachloro-l ,4-dihydrol ,4- methanonaphthalene-S,8-diol I 50 g. of l,2,3,,9,9-hexachloro-1,4,4a,8a-tetrahydro- 1,4-methanonaphthalene-5,8-dione were dissolved in 300 ml. of methanol and 3 g. of pyridine were added. The mixture was refluxed until the yellow color disappeared (about 5 hours). Upon cooling to 5-7C., white crystals separated. One recrystallization from methanol gave white crystals, m.p. 186C. The yield was almost quantitative.

The product has the following structure:

methanonaphthalene-S,8-diol Pyridine (4.1 g., 0.0437 mole) was added to a solution of compound I prepared as in Example 51 (10.0 g., 0.0262 mole) in anhydrous ether (25 ml.). A white solid began to precipitate within one-half hour. The solid was separated and recrystallized from ether. Yield 9.0 g., 75%, m.p. l-142.5C. The NMR spectrum and elemental analysis were consistent with the proposed structure.

The NMR spectrum showed 5 pyridine protons at 863 Hz, 783-741 Hz, 2 aromatic protons at 736 Hz and 2 -OH protons at 667.5 I-lz.

Anal. calcd. for C H CI NO The dione starting material was prepared as follows.

A mixture of 54.6 g. (0.2 mole) of hexachlorocyclopentadiene, 21.6 g. (0.2 mole) of p-benzoquinone, and 10 ml. of toluene were placed in a 125 ml. round bottom flask and heated for three hours so that the toluene refluxed gently. At the end of this period the reaction mixture suddenly solidified completely, indicating completion of the reaction. The crude product was bright yellow. The damp material was transferred to a Buchner funnel, rinsed with absolute ethanol, dried on the funnel, and crystallized from ethanol. 49 g. of

c1 c1 0HC1)\ 0H I E 1 01 0H 0H (I) (II) EXAMPLE 53 Preparation of molecular complex (1:2) of l,2,3,4,9,9- hexachloro-l ,4-dihydrol ,4-methanonaphthalene-5 ,8- diol and pyridinuim hydrochloride A saturated ethereal hydrogen chloride solution was added to an ethereal solution of 1.0 gm. of the complex of Example 52 .[compound II]. The white precipitate (0.8 g., m.p. 1836C) was separated by filtration. This material was identical to the material obtained by rebright yellow dense Crystals were Obtained acting compound I with thionyl chloride and pyridine.

189193C. (reported 188C). The yield was 64%. The dione product has the following structure:

The LR. and elemental analysis were in agreement with the proposed structure.

l; H. 2.64; CI, 46.35; N, 4.58. Found: C, 40.47; H, 2.

H HCI (III) EXAMPLE 54 Preparation of molecular complex (2:1) of pyridinium methobromide and compound I Methylbromide was bubbled through an ethereal solution of the complex of Example 52 [compound (ll)]( 15.0 g.) for min. The flask was stoppered and allowed to stand at room temperature for 4 days. The resulting solid material was filtered to yield 3.6 g., m.p. 2102l2C.

Anal. Calc'd. for

C H- Cl Br N O C, 37.90; H. 2.77; CI. 29.l8; H. 3.84. Found: C. 37.57; H 2.53; Cl. 29.91; N. 3.86.

01- (HI) CHgBl' 1 C1 01 QE/ OH omar EXAMPLE 55 Preparation of molecular complex (2:1') of pyridinium methoiodide and compound I This complex was prepared in a manner similar to that of Example 54 from 15 g. of compound II and 4.0 g. of methyliodide. The crude product (6.7 g.) was recrystallized from CHCl -ether to give a pure sample,

mp. 225C.

Anal. Calcd. for

C H Cl l N o z C, 33.57; H. 2.45; Cl, 25.85; N. 3.40. Found: C. 33.47; H. 2.23; CI. 26.90; N. 3.33.

c1 c1 or p11 H CHaI EXAMPLE 56 and dimethylsulfoxide Compound I, 38 g. and an excess of dimethylsulfoxide (DMSO) were mixed in benzene and stirred for minutes. The formed solid was recrystallized from benzene and white crystals were obtained, m.p. l60"/sC. NMR, IR and elemental analysis were in good agreement with the proposed structure.

Ann]. Calc'tl. for

C|:\ Cl..O;,S: C. 34.02; H. Found: C. 33.80; H.

CI. 46.42: S. 6.55.

l Preparation of the molecular complex of compound I The NMR spectrum showed 2 OH protons at 729 Hz. 2 aromatic protrons at 665 Hz and 6 DMSO pro tons at 262 Hz. Infrared analysis showed the presence of a OH group at 3300 cm and a norbomene double bond at 1600 cm.

01 (I) DMSO -DMSO EXAMPLE 57 Preparation of the molecular complex of compound I and dimethylformamide (DMF) This molecular complex was prepared by the same method as given in Example 56. The product melted at l l0-- C.

44'. Found: C. 37.74; H, 2.69;

CI. 46.86; N. 3.09. c1. 47.83; N. 3.13.

The NMR spectrum showed 2 aromatic protons at 670 Hz, 2 OH protons at 636 Hz, and 2 methyl groups at 298 Hz and 292 Hz. Infrared analysis showed the presence of an OH group at 3300 cm and a norbomene double bond at 1600 cm.

(I) DMF DMF C1 'C1 6H (VII).

EXAMPLE 58 Preparation of the molecular complex (1:2) of compound I and pyridine oxide 19 g. of compound I and 10 g. of pyridine oxide were mixed in ml. of anhydrous ether and stirred for one hour. The formed white solid was filtered off and recrystallized from benzene and white crystals were obtained, mp. l46l48C. NMR, IR and elemental analysis agreed with the proposed structure.

Anal. Calcd. for

C l-l Cl N oz C, 44.04; H. 2.45; N. 4.91.

Found: C. 43.87. H. 2.29; N. 4.7l.

The NMR spectrum showed pyridine oxide protons at 832-8 19 Hz and 740-738 Hz, 2 aromatic protons at 671 Hz, and OH protons at 819.5 Hz. Infrared analysis showed strong OH group absorption at 3000-3300 cm.

C1 C1 OH CI I I O1 O OH (VIII).

2. A flame retardant composition as claimed in claim I, wherein the polymer is an acrylonitrile-butadiencstyrene polymer and the amount of the compound is at least about 6.0 parts per 100 parts by weight of the polymer.

3. A flame retardant composition as claimed in claim 1, wherein the polymer is a polyurethane and the amount of the compound is at least about 5.0 parts per 100 parts by weight of the polymer.

4. A flame retardant composition as claimed in claim 3, wherein the polyurethane is a polyether-based polyurethane.

5. A synergistic composition for rendering a polymer flame retardant and comprising 1,2,3,4,9,9- hexachloro-l ,4-dihydro- 1 ,4-methanonaphthalene-5 ,8- diol and a synergizing amount of an additive selected from the group consisting of urea, magnesium oxide, magnesium sulfide, magnesium acetylacetonate, polyvvinylchloride, trityl chloride and TABLE IX 2 BURN RATE ABS Additive, pph of Inches/ OXY- GEN EXAMPLE (parts) Compound No. Additive Minutes Index 59 100 None 1.80 18.5 60 do. 11 10.0 1.28 27.3 61 do. 111 4.0 1.78 29.3 62 do. 111 5.8 SE 30.1 63 do. 111 10.0 NB 35.6 64 do. IV 8. l 22.5 65 (10. V 10.0 1.84 24.8 66 do. V1 10.0 1.20 27.0 67 do. VI 15.0 SE 28.0 68 do. VII 10.0 1.10 26.0 69 do. VII 15.0 SE 27.5 70 do VIII 15.0 SE 28.0 71 do Chloran 11.1 1.80 20.2 72 do Chloran 20.0 1.75 21.4 73 do Chloran 150 SE 29.8

The effectiveness of the molecular complexes of the invention as flame retardants is seen from the data in Table IX, wherein the complexes are compared with chloran.

As seen in Table IX, compound II at only a 5.8 parts per hundred level gives an oxygen index of 30.1 and a self-extinguishing composition, whereas it requires 150 parts per hundred of chloran to given an oxygen index of 29.8 and a self-extinguishing composition.

Thus, compound II is about times better than chloran according to this test. Chloran at a 25 parts per hundred level gives an oxygen index of only 21.4.

Variations and modifications can, of course, be made without departing from the spirit and scope of the invention.

Having thus described out invention, what we desire to secure by Letters Patent and hereby claim is:

l. A flame retardant composition comprising a polymer selected from the group consisting of acrylonitrilebutadiene-styrene polymers and polyurethane polymers and an effective amount of the compound, 1,2,3,- 4,9,9-hexachloro-1 ,4-dihydrol ,4-methanonaphthalene-5,8-diol.

6. A composition as claimed in claim 5, wherein the additive is urea and the weight ratio of urea to the 1,2,- 3,4,9,9-hexachlorol ,4-dihydrol ,4-methanonaphthalene-5,8-diol is about '3-6: 10.

7. A composition as claimed in claim 5, wherein the additive is magnesium oxide and the weight ratio of magnesium oxide to the l,2,3,4,9,9hexachloro1 ,4- dihydro-l ,4-methanonaphthalene-5 ,8-diol is about 8. A composition as claimed in claim 5, wherein the additive is magnesium sulfide or magnesium acetylacetonate and the weight ratio of said additive to the 1,2,- 3 ,4,9,9-hexachloro-1 ,4-dihydro-1 ,4-methanonaphthalene-5,8 diol is about 2.8:7.0.

9. A composition as claimed in claim 5, wherein the additive is polyvinylchloride and the weight ratio of polyvinylchloride to the 1,2,3,4,9,9-hexachloro-1,4- dihydro- 1 ,4-methanonapthalene-5,8-diol is about 1 5:6.

10. A compositon as claimed in claim 5, wherein the additive is trityl chloride and the weight ratio of trityl chloride to the l,2,3,4,9,9-hexachloro-b l,4-dihydro l,4-methanonaphthalene-5,8-diol is about 4.211 1.1.

1 l. A composition as claimed in claim 5, wherein the additive is O i 1 N. S. H J O z [A1 and Al(OH) 13. A flame retardant composition as claimed in claim 12, wherein the additive is urea and the weight ratio of urea to the l,2,3,4,9,9-hexachlorol ,4-dihydro- 1,4methanonaphtha1ene-5,8-diol is about 3-6: 10.

14. A flame retardant composition as claimed in claim 12, wherein the additive is magnesium oxide and the weight ratio of magnesium oxide to the 1,23,49,9- hexachlorol ,4-dihydrol ,4-methanonaphthalene-5 ,8- diol is about l.44.4:7.7-l0.

15. A flame retardant composition as claimed in claim 12, wherein the additive is magnesium sulfide or magnesium acetylacetonate and the weight ratio of said additive to the l,2,3,4,9,9-hexachloro-l ,4-dihydrol ,4 methanonaphthalene-5,8-diol is about 2.8:7.0.

16. A flame retardant composition as claimed in claim 12, wherein the additive is polyvinylchloride and the weight ratio of polyvinylchloride to the l,2,3,4,9,9- hexachlorol ,4-dihydro- 1 ,4-methanonaphthalene-5 ,8- diol is about 15:6.

17. A flame retardant composition as claimed in claim 12, wherein the additive is trityl chloride and the weight ratio of trityl chloride to the l,2,3,4,9,9- hexachloro-l ,4-dihydrol ,4-methanonaphthalene-5 ,8-- diol is about 42:11.1.

18. A flame retardant composition as claimed in claim 12, wherein the additive is and the weight ratio thereof to the l,2,3,4,9,9- hexachloro- 1 ,4-dihydro-l ,4-methanonaphthalene-5 ,8- diol is about 310:l0.

OF CORECTION 247-16-c11 Patent No. 3,832,422 Dated Augu'st 27 1 ImmncM-(M Julian R. Little et a].

It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

r I I a w Column 5, line 39: "polyisocyantes" should read polyisocyanates Column 5, line 40: "diisocyantes" should read diisocyanates Columns 5-6, Example 1 of Table II, in column 'BURN RATE Inches/Minutes": "18.3" should read 1.80 Columns 5-6, Example 1 of Table II, in column "OXYGEN IndexZJ': first line should read 18.3

Column 9, line 16: "increase 4.7%" should read increase of 4.7% M,

Columns 11-12, Table VIII; in the heading:

BURN ADDITIVES (pans) RATE 1 A85 DECHLO- Inches] 'OXY- RAN GEN g EXAMPLE aru) COMPOUND PVC 602 Minutes lndex% I m should read:

BURN ADDITIVES (p RATE ABS DECHLO- Inches] OXY- RAN GEN EXAMPLE (pans) COMPOUND PVC 602 Minutes Index% @2353? UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No. 3,832,422 Dated August 27, 1974 Inventofls) Julian R. Little et al P 2 It is certified that error appears in the above-identified patent and that: said Letters Patent are hereby corrected as shoyn below:

Column ll, line 21: "1,2,3, +-9-hexachloro-" should read l,2 3,4,9,9hexachlorq p Column 13, line 23: "(III)+CH Br -9 should read (II)+CH Br Column 13, line 48:

"(III)-l-CH should read (IIHCH I Column 13, line 62: "l60-7/8C. should read l60-l62C.'-.

Column 14, line 2: "protrons" should read protons Column 15, line 52: "to given an" should read to give an Column 15, line 60: "out" should read our Column 17, line 34: Take our entire line.

Signed and sealed this 5th day of November 1974.

(SEAL) Attest:

MCCOY M. GIBSON JR. C. MARSHALL DANN Attesting Officer Commissioner of Patents 

2. A flame retardant composition as claimed in claim 1, wherein the polymer is an acrylonitrile-butadiene-styrene polymer and the amount of the compound is at least about 6.0 parts per 100 parts by weight of the polymer.
 3. A flame retardant composition as claimed in claim 1, wherein the polymer is a polyurethane and the amount of the compound is at least about 5.0 parts per 100 parts by weight of the polymer.
 4. A flame retardant composition as claimed in claim 3, wherein the polyurethane is a polyether-based polyurethane.
 5. A synergistic composition for rendering a polymer flame retardant and comprising 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol and a synergizing amount of an additive selected from the group consisting of urea, magnesium oxide, magnesium sulfide, magnesium acetylacetonate, polyvinylchloride, trityl chloride and
 6. A composition as claimed in claim 5, wherein the additive is urea and the weight ratio of urea to the 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 3-6:10.
 7. A composition as claimed in claim 5, wherein the additive is magnesium oxide and the weight ratio of magnesium oxide to the 1, 2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 1.4-4.4:7.7-10.
 8. A composition as claimed in claim 5, wherein the additive is magnesium sulfide or magnesium acetylacetonate and the weight ratio of said additive to the 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 2.8:7.0.
 9. A composition as claimed in claim 5, wherein the additive is polyvinylchloride and the weight ratio of polyvinylchloride to the 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonapthalene-5,8-diol is about 15:6.
 10. A compositon as claimed in claim 5, wherein the additive is trityl chloride and the weight ratio of trityl chloride to the 1, 2,3,4,9,9-hexachloro-b 1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 4.2:11.1.
 11. A composition as claimed in claim 5, wherein the additive is
 12. A flame retardant composition comprising an acrylonitrile-butadiene-styrene polymer and an effective amount of a composition comprising 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol and a synergizing amount of an additive selected from the group consisting of urea, magnesium oxide, magnesium sulfide, magnesium acetylacetonate, polyvinylchloride, trityl chloride and
 13. A flame retardant composition as claimed in claim 12, wherein the additive is urea and the weight ratio of urea to the 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 3-6:10.
 14. A flame retardant composition as claimed in claim 12, wherein the additive is magnesium oxide and the weight ratio of magnesium oxide to the 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 1.4-4.4:7.7-10.
 15. A flame retardant composition as claimed in claim 12, wherein the additive is magnesium sulfide or magnesium acetylacetonate and the weight ratio of said additive to the 1,2, 3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 2.8:7.0.
 16. A flame retardant composition as claimed in claim 12, wherein the additive is polyvinylchloride and the weight ratio of polyvinylchloride to the 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 15:6.
 17. A flame retardant composition as claimed in claim 12, wherein the additive is trityl chloride and the weight ratio of trityl chloride to the 1,2,3,4,9,9-hexachloro-1,4-dihydro-1,4-methanonaphthalene-5,8-diol is about 4.2:11.1.
 18. A flame retardant composition as claimed in claim 12, wherein the additive is 